Writing instrument



July 20, 1954 E, w. RICKMEYER WRITING INSTRUMENT Filed Sept. 11, 1948Patented July 20, 1954 UNITED STATEt OFFICE WRITING INS TRUMEN'LApplication September 11, 1948, Serial No. 48,836

14 Claims. 1

This invention relates to ink-writing instruments and has to do moreparticularly with an instrument of the type having a capillary inkstorage reservoir.

An object of this invention is to provide an improved Writing instrumentof the foregoing type.

Another object is to provide an improved capillary filler and reservoirelement for a writing instrument.

Another object is to provide a capillary filler and reservoir elementwhich is simple and inexpensive to manufacture and assemble, rugged inconstruction, and which has a relatively large ink storage capacity.

Another object is to provide an improved capillary filler element formedfrom porous sintered metal.

Another object is to provide a writing instrument adapted to be filledeither by dipping the writing point into a supply of ink or by insertingin the instrument an ink-containing cartridge.

Other objects and advantages of the invention will appear from thefollowing description taken in connection with the appended drawings,wherein:

Figure l is a longitudinal sectional view of a preferred embodiment ofmy invention;

Fig. 2 is an enlarged, transverse, sectional View taken along line 2-2of Fig. 1;

Fig. 3 is an enlarged, transverse, sectional view taken along line 3-3of 1; and

Fig. 4 is an enlarged, transverse, sectional View taken along line i ofFig. 1.

Referring now particularly to Fig. l, the inkwriting instrument includesa barrel or casing which preferably is formed by a forward barrelsection iii and a rear barrel section or end cap I i detachablyconnected as by a threaded sleeve i2. While the barrel may be formed ofbarrel sections of nearly equal size, or with a long rear barrel sectionand a short forward barrel section, I prefer to employ a constructionsuch as that illustrated. The barrel defines a chamber 53 adapted toreceive a capillary filler element and an ink cartridge, both of whichare described more in detail hereinafter.

A capillary filler and reservoir element is formed to provide a largenumber of interconnected spaces of capillary size, adapted to draw inktherein when placed in ink-feeding communication with a supply of inkand to retain the ink therein by capillary action except when thewriting point is placed in contact with a writing surface.

Mil-42.16)

The capillary filler and reservoir element includes a plurality ofdisc-like members is formed of porous sintered material. Each of themembers is formed with an annular rim portion l5 and a dished centralportion It of generally conical form. The members :4 are so formed thatthey may be stacked, as illustrated in Fig. 1, to define between the rimportions 15 annular spaces H which are of capillary depth, thusproviding a plurality of annular capillary ink storage spaces adapted toreceive and store inl: therein. Moreover, the porous metal from whichthe members it are formed has interconnected pores or spaces therein ofcapillary size also adapted to retain ink by capillary action. The poresin the members 14 communicate with and provide means interconnecting theseveral capillary spaces ll. Preferably, the pores in the mer sers itare of slightly smaller size and therefore greater capillarity than thespaces ii and thus ink will be drawn into the pores of the members itfrom the capillary spaces ll and, since th members M are in firmabutment over substantial portions of their respective areas, aplurality of continuous interconnected columns of ink are formed in thestack of members it. EX- cellent results have been obtained by makingthe pores in the members M of a size around 0.005" in wall-to-wallthickness and the capillary spaces ll of slightly greater depth. Thefiller element members 14, as well as the Writing element and feedelement hereinafter described, is formed in the manner disclosed in myco-pending application Serial N-o. 45,823 filed August 24, 1948.

Each of the reservoir element members i i is provided with a central airvent opening [5 and, when the several members I i are disposed instacked relation, the several air vent openings i 8 thereof aresubstantially in alignment and define with spaces l9 between adjacentdished portions it an air vent passage extending longitudinallythroughout the reservoir element. Thus, an air vent passage is providedthrough which air may pass during the filling or writing operations, ashereinafter described.

The barrel at its forward end is provided with a bore 2% adapted toreceive and seat a writing element 2%. The writing element preferably isformed of porous sintered metal generally similar to the metal fromwhich the members I4 are formed and this element preferably takes theform of a hollow, elongated cup-like member open at its rear end andclosed at its forward end. The forward end of the writing element 2! isrounded, as illustrated, to provide a smooth writing tip.

The writing element 2| is connected in inkfeeding relation to the fillerelement by a feed element 23 having an enlarged head portion 24 disposedsnugly in a reduced bore 25 extending forwardly from the chamber |3. Thefeed element 23 also has a reduced body portion 28 which extendsforwardly through a reduced bore 21 and into the rear open end or" thewriting element 2|. The body portion 25 preferably is of generallysquare cross-sectional shape but has rounded corners 28 whichfrictionally and firmly seat against the inner wall surface of thewriting element 2|. The feed element 23 is formed of porous sinteredmetal generally similar to that from which the filler element members Mand the writing element 2! are formed. The feed element is firmlyabutted at its rear face by the forwardmost reservoir element member i4and, as previously explained, i also in firm contact with the writingelement 2 whereby the pores in the feed element 23 serve to connect thepores of the forwardmost reservoir element member M with the pores ofthe writing element 2|.

The writing element 2| is held against rearward displacement by aforwardly facing shoulder 3|] and the feed elements 23 is held againstforward displacement by a rearwardly facing shoulder 3|, these elementsbeing further retained against dislodgment by frictional engagement withthe bores 28 and 25 respectively and by frictional en gagement with eachother.

The interior of the writing element 2| defines a space 22 which aids inproviding a venting action, hereinafter explained more in detail, andadditional venting is provided by air channels 32 formed between thestraight side walls of the body 26 and the adjacent curved walls of thewriting element 2|. In addition, venting grooves 33 are formed in theforward end face of the enlarged head 24, which grooves extend radiallyoutwardly from the juncture of the head 24 and body 26.

The pen of the present invention is adapted to be filled by capillaryaction, where such type of filling is desired. To fill the pen, thewriting element is inserted in a supply of ink and ink rises bycapillary action in the writing element, thence into the feed elementand thence into the reservoir element members l4 successively from thelowermost to the uppermost. Ink also may enter the capillary spaces lldefined between the peripheral portions it: of adjacent members l4.

The present invention also provides means for filling the pen from anink cartridge 49 by merely removing the rear end cap H and inserting theink cartridge in the pen, whereupon ink flows from the ink cartridgeinto the reservoir element to fill the latter and is retained therein bycapillary action until it is withdrawn in writing. One form of inkcartridge suitable for use in the pen of the present invention isillustrated in Fig. 1 of the drawing. The cartridge is removable fromthe barrel and is adapted to be filled with ink by the manufacturer anddispensed as a filled cartridge which may be inserted in the writinginstrument by the user. The cartridge is so formed as to prevent inkfrom leaking therefrom when the cartridge is stored or shipped, but isadapted to be placed in condition for use by merely inserting it in thebarrel of the writing instrument.

The cartridge d9 preferably includes a tubular casing 4!, closed at itsforward end by an imerforate, puncturable closure member 42 formed ofrubber or equivalent material and suitably secured, as by an adhesive inthe forward end of the casing 4|, in such manner as to prevent leakageof ink from the casing so long as the closure member remainsimperforate.

The rear end of the casing 4| is closed by a closure member 43 adaptedto prevent ink from leaking from the casing, but at the same timeadapted to permit air to enter the casing to permit ink to flow from thecasing when the closure 42 is punctured. Preferably, the rear endclosure is formed of porous sintered metal generally similar to thatabove described and having pores of such size as to permit air to passtherethrough but sufiiciently fine to prevent ink from leaking from therear end of the casing. The rear end closure is suitably secured in therear end of the casing to prevent dislodgment during handling.

The interior of the casing 4| is vented through the rear end closure 43and, when the cartridge is in position in the barrel ID, the interior ofthe casing is vented to the exterior of the pen through a vent slot 44formed in the metal sleeve l2 and a port 45 suitably located, as, forexample, at the juncture of the barrel l0 and rear end cap I I. In orderto insure the desired venting action, a seating element 48 is providedwhich takes the form of a disc of material similar to the rear endclosure member 43'. The disc 45 is snugly seated in the rear end cap Hin position to be abutted by the rear end closure II when the cartridge40 is assembled in the barrel l0 and the rear end cap I is in position.

Means are provided for puncturing the closure 42 and for permitting inkto pass from the cartridge to the filler and reservoir element, whichmeans preferably takes the form of a channel element 50 having a tubularportion 5| and a head portion 52, with a bore 53 extending through boththe tubular and head portions. The head portion 52 abuts the rearmostmember M of the reservoir element and is adapted to itself be abutted bythe forward end of the ink cartridge 48 when the latter is moved intoits home position in the barrel. The head 52 is snugly and frictionallysecured in the barrel l0 and serves to maintain the members M inabutting relation and also to maintain the forwardmost member M inabutment with the feed element 23. The rearward end of the tubularportion 5| is sharpened and adapted to puncture the forward closuremember 42 to permit the rearward end of the tubular member to enter theinterior of the casing 4| and to place the interior in communicationwith the exterior through a bore 52. Thus, when the cartridge 49 ismoved into home position, the closure 42 is punctured and ink will fiowfrom the cartridge into the chamber I3 forwardly of the head 52 and bedrawn into the capillary spaces provided in the reservoir element toplace the instrument in condition for writing.

It will be noted that a vent passage is provided through the bore 53,the interior of the casing 4|, the rear closure 43, the seating member46, the channel groove 44 and the port 45. Thus, air which is in thecapillary spaces in the filler element, and which is displaced by theink as it flows into the filler element, may pass upwardly through thecentral openings IS in the reservoir element members I4 and bubbles upthrough the ink in the passage 52 and in the casing 4|, and escapesthrough the rear closure 43 as above indicated.

In writing, when the forward end of the writing element is placed incontact with the writing surface, the capillarity thus established drawsink from the writing element, and ink to replace the withdrawn ink isdrawn into the writing element from the feed element, ink being drawnfrom the reservoir element into the feed element. Air to replace inkwhich is drawn from the reservoir element enters the instrument throughthe port 45 and passes through the slot All and through the cartridgecasing M, where a cartridge is employed, or through the rear end of thebarrel where no cartridge is employed. The air then passes through thepassage 52 and through the central openings B8 of the filler elementmembers [4.

It has been found that where a porous capillary member of substantialwall thickness is employed, locking of the ink columns may occur due tothe inability of air to enter the pores behind the ink, thus causing anuneven withdrawal of ink or even complete stoppage of the passage ofink, especially where the writing instrument is employed in rapidwriting. In order to permit ink to pass readily along the spaces orpores in the feed element 23 and the writing element 2! to replace inkwithdrawn from the latter in writing, the writing element, and preferably, also, the feed element, are so formed and arranged that thereare no relatively thick crosssectional areas therein and atmosphericpressure is applied to the surfaces of these elements on opposite sidesof relatively thick wall portions. Thus, as ink is withdrawn from thewriting element, air enters the pores and prevents any restriction onthe passage of ink or lookingf which might otherwise occur were the feedelement and writing element not thus vented.

The writing element is formed as a hollow member having therein a space22 forwardly of the feed element, which space under normal con ditionscontains air at atmospheric pressure. A substantial portion of theexterior surface of the writing element is exposed and, therefore, italso is subjected to atmospheric pressure. The feed element is vented bythe vents 32' and 33 above described.

Since air at atmospheric pressure is normally in contact with both theinner and outer faces, the ink in the pores of the writing elementnormally is under atmospheric pressure and, therefore, flows evenlyalong the pores as ink is withdrawn from the tip in writing. However,since air will enter the empty pores more rapidly than ink, some air maybe drawn into the pores as the ink is withdrawn, some or this air beingdrawn in from the outside and some from the inside of the writingelement. Air will normally find its way through the wall of the writingelement at some point and thus maintain atmospheric pressure within thespace 22. The feed element 23 is vented in a generally analogous mannerinasmuch as the rear face is exposed to atmospheric pressure by way ofthe vent openings as in the members I l, and the forward face of thehead and the'side faces of the body of the feed element are vented bythe passages 32 and 33, respectively.

A further aid to the venting action may be provided by forming thewriting element with somewhat larger pores in the upper portion Zia ofthe forward end than in the lower portion Bib, which latter portion isnormally adapted to contact the writing surface. Thus, ink will tend tobe drawn into the smaller pores which have the greater capillarity andaway from the larger pores, thereby permitting air to enter the interiorof the writing element through the larger pores. This difference in poresize may be provided by suitably forming the sintered metal member.Accordingly, during the molding of the powdered material prior tosintering that portion of the material which is to form the portion ofthe element having the pores of smaller size is compacted to a greaterextent than the portion of the material which is to form the portionhaving the pores of greater size. When the molded material is sintered,the pores will be of a smaller size in those portions of the memberwhich were more greatly compacted during the molding operation.

It will be seen from the foregoing that the present invention provides awriting instrument which is simple in construction and can be maderelatively inexpensively. The several members which are formed fromsintered material lend themselves readily to formation in the mannerdescribed and they may be assembled in the barrel without the exerciseof unusual skill. Moreover, the construction of the instrument is suchthat there are no highly critical dimensions or tolerances and,therefore, the pen will operate even should slight departures from thedesired dimensions occur during manufacture.

The writing element is of such form and so mounted that there is nolikelihood of clogging of the ink flow passages by lint from the pocketof the user or fibers or sizing material from the paper with which theinstrument is used in writmg.

The instrument is adapted for use with conventional inks of the typescommonly used in fountain pens and does not require any special type ofink for its operation. It may be filled by inserting an ink cartridge inthe barrel, the cartridge being of such nature that it can be readilystored, shipped and dispensed and when inserted in the barrelautomatically fills the reservoir element to place it in condition forwriting. On the other hand, Where a cartridge is not available or whereit is preferred not to fill the pen in this manner, the pen may befilled by merely dipping the writing element in a supply of ink,whereupon the pen fills itself automatically by capillary action.

The venting action provides an even, controlled flow of ink to thewriting element so that a uniform writing action is provided.

I claim:

1. A writing instrument comprising a barrel, a capillary filler andreservoir element in said barrel including a plurality of members formedfrom porous sintered metal, the pores of which are interconnected andare of capillary size and provide capillary ink storage spaces, saidmembers being of generally disc form and disposed in a stack withportions of adjacent members mutually spaced and defining therebetweencapillary ink storage cells or" greater dimension than the andcommunicating therewith, said pores and cells constituting the principalink storage spaces of the pen, and a writing element connected in inkfeeding relation to said filler and reservoir element.

2. A wr ing instrument comprising a barrel, a capillary filler andreservoir element in said barrel including a plurality of members formedfrom porous sintered metal, the pores of which are interconnected andare of capillary size and provide capillary ink storage spaces, saidmembers being of generally disc form and disposed in a stack withportions of adjacent members mutually spaced and defining therebetweencapillary ink storage cells of greater dimension than the pores in saidmembers and communicating therewith, each of said members being providedwith an opening extending therethrough larger than said cells, saidopenings together providing an air vent passage extending through saidfiller and reservoir element, and a writing element connected in inkfeeding relation to said filler and reservoir ele ment.

3. A writing instrument comprising a barrel, and a capillary filler andreservoir element in said barrel including a plurality of members formedfrom porous sintered metal, the pores of which are interconnected andare of capillary size and provide capillary ink storage spaces, saidmemhere being of generally disc form and disposed in a stack withportions of adjacent members mutually spaced and defining therebetweencapillary ink storage spaces of greater dimension than the pores in saidmembers and communicating therewith, a writing element formed of poroussintered metal, the pores of which provide capillary ink feed channels,and a feed element formed of porous sintered metal, abutting saidWriting element and at least one of said members, the pores of said feedelement providing capillary ink feed channels connecting the ink storagespaces of said filler and reservoir spaces with the ink feed channels ofsaid writing element.

4. A capillary filler and reservoir element including a plurality ofmembers of porous material arranged in a stack, the pores of whichmembers are interconnected and provide capillary spaces, said membershaving central dished portions adapted to interfit and space theremainder and peripheral poition of each member from the adjacentmembers to provide a capillary ink storage space between adjacentmembers, said spaces being of greater dimension than said pores forenabling free and unobstructed flow of air therethrough.

5. A writing instrument comprising a barrel having an opening at itsforward end and having its rear end vented to atmosphere, a capillaryfiller and reservoir element in said barrel for rebarrel and having acapillary passage for ink leading from the filler and reservoir elementto the forward end of the writing element, whereby said filler andreservoir element is capable of being filled by capillary action throughthe writing element when the latter is placed in communication with asupply of ink, an ink cartridge adapted to contain ink, the capacity ofsaid cartridge being not greater than that of said capillary filler andreservoir element, said cartridge being removably disposed in saidbarrel rearwardly of said capillary filler and reservoir element andhaving a puncturable closure at its forward end, and having meansincluding a capillary element at its rear end for confining the ink inthe cartridge but capable of admitting air into the cartridge, and achannel member between said filler and reservoir element and cartridgehaving a tubular portion positioned to extend through said puncturableclosure when the cartridge is in position in said barrel to provide apassage for ink from the cartridge.

6. A writing instrument comprising a barrel vented at its rear end, acapillary filler and res ervoir element in said barrel and consisting ofporous sintered material and having an air passage throughout its lengthof greater dimension than the pores of the material, and a capillarywriting element of porous sintered material of hollow shell-like formand having a closed forward end and including a defining wall elementwith pores distributed throughout and opening through the outer andinner surfaces thereof, said pores being in capillary ink feedingrelation with said filler and reservoir element, said writing elementhaving a substantial interior surface and having an exterior surface ofsubstantial dimensions exposed through the forward end of the pen.

7. A writing instrument comprising a barrel vented at its rear end, acapillary filler and reservoir element in said barrel and consisting ofporous sintered material, and a capillary writing element of poroussintered material in capillary ink feeding relation with said filler andreservoir element, said writing element being of tubular form with aclosed end extending forwardly through the forward end of the barrel,said closed end having an upper and a lower portion with respect to awriting position whereby the lower portion is adapted to engage awriting surface in writing, the pores in said upper portion throughoutthe thickness of the element at that portion being of greater dimensionand lesser capillarity than the pores in said lower portion, said poresof greater dimension providing passage for air from the exterior to theinterior of the writing element.

8. A capillary filler and reservoir element including a plurality ofmembers of porous sintered material arranged in a stack, the pores ofthe members being interconnected and providing capillary spaces, eachmember having an annular substantially flat peripheral portion and acentral dished portion, the dished portion having a central flat portionon its outer convex surface and a central air passage through the dishedportion of greater dimension than the pores of the material, said dishedportions being interfitted when the members are stacked and being soshaped that the peripheral portions are mutually spaced apart to formcapillary spaces of greater dimension than the pores of the material,and the central portions of the dished portions are mutually spacedapart to form central spaces of greater dimension than the pores of thematerials, the central spaces and air passages forming a continuous airpassage throughout the length of the filler and reservoir element.

9. A capillary filler and reservoir element including a plurality ofmembers of porous material arranged in a stack with each of said membershaving a projecting portion abutting an adjacent member over asubstantial area to space the remaining portions of adjacent members adistance such that the spaces are of greater dimension than the pores,said spaces opening through to the exterior of the filler and reservoirelement, the pores of said members being interconnected and defining acapillary ink storage space in each member communicating in inkfeedingrelation with those of abutting members and with the spaces betweenitself and such abutting members.

10. An ink storage member for a capillary filler and reservoir elementcomprising a generally disc-like member formed of porous sintered metal,the pores of which are interconnected and open through the surface ofthe member substantially throughout the area of the latter, said poresproviding capillary ink storage spaces, said memher having a dishedcentral portion and an annular substantially flat peripheral portion,said dished portion having complementally shaped concave and convexsurfaces, the greatest transverse dimension of the concave surface beinggreater than the least transverse dimension of the convex surface.

11. An ink storage member for a capillary filler and reservoir elementcomprising a generally disk-like member formed of porous sintered metalthe pores of which are interconnected and exposed throughout the surfaceof the member, said pores providing capillary ink storage spaces, saidmember being formed with an air Opening extending therethrough of largersize than said pores, and having a plane portion and a second portionextending out of the plane of the plane portion, said second portionbeing so shaped on opposite sides that a plurality of identical saidmembers can be stacked with the second portions inter-engaging and theplane portions mutually spaced apart, and with the air openings inalignment.

12. A writing instrument comprising a barrel, a capillary filler andreservoir element in said barrel including a plurality of rigid andporous members, the pores of which are interconnected and of capillarysize and provide capillary ink storage spaces, said members being ofgenerally disc form and disposed in a stack with portions of adjacentmembers mutually spaced and defining therebetween capillary ink storagecells of greater dimension than the pores in said members andcommunicating therewith, said pores and cells constituting the principalink storage spaces of the pen, and a writing element connected in inkfeeding relation to said filter and reservoir element.

13. A writing instrument comprising a barrel, a capillary filler andreservoir element in said barrel including a plurality of individual andseparate stacked discs, each disc having pores of capillary size and thediscs forming between abutting ones thereof pores of capillary size, anda writing element connected in ink feeding relation to said filler andreservoir element.

14. A writing instrument comprising a barrel having a reservoir chamber,a capillary filler and reservoir element in said chamber including aplurality of individual and separate discs, said discs being arrangedtransversely and stacked in the longitudinal direction of the chamber,said discs having outline size and shape substantially identical withthe cross sectional size and shape of the chamber, adjacent ones of saiddiscs abutting in mutual relation throughout at least a substantialportion of their transverse extent and the discs being supported instacked relation by the abutment between the discs and substantiallyconfined by the surrounding side walls of the chamber, each disc havingpores of capillary size with at least certain ones opening through theabutting surfaces of the discs, and the discs forming between abuttingones thereof pores of capillary size defined by the open-sided pores inthe respective discs, and a writing element connected in ink feedingrelation to the filler and reservoir element.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,890,100 Spiro Dec. 6, 1932 2,157,596 Davis May 9, 19392,223,541 Baker Dec. 3, 1940 2,229,749 Little Jan. 28, 1941 2,233,846Packard Mar. 4, 1941 2,282,840 Wing May 12, 1942 ,283,333 Martin May 19,1942 2,297,817 Truxell et al. Oct. 6, 1942 2,368,425 Reynolds Jan. 30,1945 2,396,058 Rath Mar. 5, 1946 2,396,101 Hensel et al. Mar. 5, 19462,462,929 Zodtner Mar. 1, 1949 2,522,555 Bartell Sept. 19, 1950 FOREIGNPATENTS Number Country Date 526,288 Great Britain Sept. 13, 1940 703,046Germany Feb. 27, 1941

